Plasmon-polariton emission from a coherently p-excited quantum dot near a metal interface

We study the emission of surface plasmon polaritons by the decay of the lowest excited state of a quantum emitter when the system is excited by a laser in resonance with a higher excited state (p-shell excitation). By solving a master equation and by using the quantum-regression theorem, we show how the emission is enhanced by the Purcell effect due to the weak coupling between the emitter and the structured spectral density of plasmon-polariton states of a metal surface. Measurable magnitudes, as the spectrum and the second-order coherence function, are extremely affected by the coherent p-shell excitation. In many cases, such coherent excitation completely masks the physical features of the emission under study. The coexistence between coherent p-shell excitation in the first step of the process and weak coupling in the final step is very important and completely general for any structured reservoir of final states. The advantage of our system is that, just by changing the distance from the quantum emitter to the metal surface, one can access a very rich set of regimes as purely dissipative direct photon emission or emission of plasmon polaritonsThis work was supported by the Spanish MICINN under Contracts No. MAT2008-01555 and No. MAT2011-22997and by CAM under Contract No. S-2009/ESP-1503. C.S.-M. acknowledges a grant from the Universidad Autonoma de Madrid. A.G.-T. acknowledges an FPU Grant No. AP2008-00101 from the Spanish Ministry of Educatio

Ecuadorian Amazonian Fruits: A Proposal to Value Biodiversity and Promote Food Sovereignty

Fruits are characterized as a source of vitamins and minerals, recognized as an important part of a healthy eating pattern that reduces the risk of some chronic diseases. The Ecuadorian flora in the Amazon region is rich in edible fruits, but little is known about their characteristics and nutritional importance. At the same time, over the years, traditional knowledge about them has been lost. With this implication, this work pretends to describe a research proposal that values the biodiversity of edible fruits in the Ecuadorian Amazon, so that these underutilized products are conceived as more than merchandise. For this purpose, a narrative bibliographic review and a participatory observation were carried out. The research proposal included three stages i) the characterization of fruits traded in local markets; ii) an ethnobotanical study to identify the use and preference of the fruits; and iii) the analysis of bioactive compounds of at least 5 fruits prioritized according to the characterization and ethnobotanical study. The proposal stages generated research that converges the valuation of biodiversity, traditional knowledge, and nutritional potential of Ecuadorian Amazonian fruits. Keywords: edibles, characterization, bioactives, Ecuador, ethnobotany. Resumen Las frutas se caracterizan por ser una fuente de vitaminas y minerales, reconocidas como una parte importante de un patrón de alimentación saludable que reducen el riesgo de algunas enfermedades crónicas. La flora ecuatoriana en la región amazónica es rica en frutas comestibles, pero muy poco se conoce sobre sus características e importancia nutricional. A su vez, con el pasar de los años se está perdiendo el conocimiento tradicional sobre estas. Con esta implicación, este trabajo busca describir una propuesta de investigación que valore la biodiversidad de las frutas comestibles presentes en la Amazonía ecuatoriana para que estos productos infrautilizados sean concebidos como algo más que mercancías. Para esto se realizó una revisión bibliográfica narrativa y una observación participativa. La propuesta resultante incluyó tres etapas i) la caracterización de las frutas comercializadas en los mercados locales ii) un estudio etnobotánico que identifique el uso y preferencia de las frutas y iii) el análisis de compuestos bioactivos de al menos 5 frutas priorizadas de acuerdo con la caracterización y estudio etnobotánico. Las etapas de la propuesta generaron una investigación que converge la valoración de la biodiversidad, el conocimiento tradicional y el potencial nutricional de las frutas amazónicas ecuatorianas. Palabras Clave: comestibles, caracterización, bioactivos, Ecuador, etnobotánica

VIMOS-VLT spectroscopy of the giant Ly-alpha nebulae associated with three z~2.5 radio galaxies

The morphological and spectroscopic properties of the giant (>60 kpc) Ly-alpha nebulae associated with three radio galaxies at z~2.5 (MRC 1558-003, MRC 2025-218 and MRC 0140-257) have been investigated using integral field spectroscopic data obtained with VIMOS on VLT. The morphologies are varied. The nebula of one source has a centrally peaked, rounded appearance. In the other two objects, it consists of two spatial components. The three nebulae are aligned with the radio axis within <30 deg. The total Ly-alpha luminosities are in the range (0.3-3.4) x 1e44 erg s-1. The Ly-alpha spectral profile shows strong variation through the nebulae, with FWHM values in the range ~400-1500 km s-1 and velocity shifts V~120-600 km s-1. We present an infall model which can explain successfully most Ly-alpha morphological and spectroscopic properties of the nebula associated with MRC 1558-003. This adds further support to our previous conclusion that the _quiescent_ giant nebulae associated with this and other high redshift powerful radio galaxies are in infall. A problem for this model is the difficulty to reproduce the large Ly-alpha FWHM values. We have discovered a giant (~85 kpc) Ly-alpha nebula associated with the radio galaxy MRC 0140-257 at z=2.64. It shows strikingly relaxed kinematics (FWHM2) radio galaxies.Comment: 14 pages, 13 figures. Accepted for publication in MNRA

Glucocorticoids improve acute dizziness symptoms following acute unilateral vestibulopathy.

Acute unilateral vestibulopathy (AUV) is characterized by acute vertigo, nausea, and imbalance without neurological deficits or auditory symptomatology. Here, we explore the effect of glucocorticoid treatment on the degree of canal paresis in patients with AUV, and critically, establish its relationship with dizziness symptom recovery. We recruited consecutive patients who were retrospectively assigned to one of the two groups according to whether they received glucocorticoid treatment (n = 32) or not (n = 44). All patients underwent pure-tone audiometry, bithermal caloric testing, MRI brain imaging, and were asked to complete a dizziness handicap inventory on admission to hospital and just prior to hospital discharge. In the treatment group, the canal paresis at discharge was significantly lower than in the control group (mean ± SD % 38.04 ± 21.57 versus 82.79 ± 21.51, p < 0.001). We also observed a significant reduction in the intensity of nystagmus in patients receiving glucocorticoid treatment compared to the non-treatment group (p = 0.03). DHI test score was significantly lower at discharge in the treatment group (mean ± SD % 23.15 ± 12.40 versus 64.07 ± 12.87, p < 0.001), as was the length of hospital stay (2.18 ± 1.5 days versus 3.6 ± 1.7 days, p = 0.002). Glucocorticoid treatment leads to acute symptomatic improvement, with a reduced hospital stay and reduction in the intensity of acute nystagmus. Our findings suggest that glucocorticoids may accelerate vestibular compensation via a restoration of peripheral vestibular function, and therefore has important clinical implications for the treatment of AUV

The response of a neutral atom to a strong laser field probed by transient absorption near the ionisation threshold

We present transient absorption spectra of an extreme ultraviolet attosecond pulse train in helium dressed by an 800 nm laser field with intensity ranging from $2times10^{12}$ W/cm$^2$ to $2times10^{14}$ W/cm$^2$. The energy range probed spans 16-42 eV, straddling the first ionisation energy of helium (24.59 eV). By changing the relative polarisation of the dressing field with respect to the attosecond pulse train polarisation we observe a large change in the modulation of the absorption reflecting the vectorial response to the dressing field. With parallel polarized dressing and probing fields, we observe significant modulations with periods of one half and one quarter of the dressing field period. With perpendicularly polarized dressing and probing fields, the modulations of the harmonics above the ionisation threshold are significantly suppressed. A full-dimensionality solution of the single-atom time-dependent Schr odinger equation obtained using the recently developed ab-initio time-dependent B-spline ADC method reproduce some of our observations

On the minimal thermal habitability conditions in low income dwellings in Spain for a new definition of fuel poverty

Fuel poverty can be defined as “the inability to afford adequate warmth in the home”. The concept was firstly developed due to health risks related to cold among low income households. However, in the last few decades, especially since the summer heat wave of 2003 that caused 35,000 deaths across Europe, a lot of research has been conducted about the health risks related to high temperatures. Along with advances in knowledge related to the health risks associated with inadequate temperatures, several directives of the European Commission related to energy regulation urge Member States to develop their own fuel poverty definitions. This need of a methodological development for new definitions poses several questions. First, what should be the temperature thresholds for the overheated season? But, furthermore, are existing temperature baselines adequate for the Spanish context and climate? This paper presents a preliminary approach to define these new temperature thresholds for the Spanish context through the adaptive comfort model criteria. For that purpose, a statistically representative dwelling building typology of vulnerable household spaces was used to analyze indoor thermal temperatures and hence, to establish minimal energy requirements so as to achieve minimal habitability conditions

Prophylactic corneal crosslinking in myopic small-incision lenticule extraction - Long-term visual and refractive outcomes

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